The bug
Since snapshot 13w47c, Minecraft has support for native fullscreen (using the green button in the title bar) on macOS; a later update also allowed control+command+F to toggle this. However, Minecraft's built-in fullscreen mode, accessible through video settings or by pressing the F11 key (possibly with fn or ctrl also held down; see also MC-268226), can be toggled independently of this. Toggling these two features in a certain order can lead to the Minecraft window being black, blurry, unresponsive, without a title bar, partially split into a separate "java" window, and/or otherwise glitched.
How to reproduce
Launch the game. Disable Minecraft fullscreen if it is enabled.
Activate native fullscreen.
Activate Minecraft fullscreen. The Minecraft window switches to a desktop space and blocks out the other content, deactivating native fullscreen in the process; this is as expected.
Reactivate native fullscreen using ⌘⌃F. Visually, nothing will happen.
Deactivate Minecraft fullscreen. You may need to try this a few times. The screen may have visual glitches. (In some cases these can be fixed by switching to another application and back.)
Play around a bit more. See if you can get the Minecraft window to a similar state as in the screenshots below. If you get a window which is partially black or blurry, activate Mission Control (F3); you can see that the black/blurry bit is a separate window called "java".
Linked issues
is duplicated by 8
MC-40913
Mac OS X fullscreen bug, minor
Resolved
MC-52901
Fullscreen bug Mac OS X
Resolved
MC-73238
Using F11 while minecraft is in mac's full screen, a black bar is displayed
Resolved
MC-73274
OS X 10.10
Resolved
MC-146335
Weird window behavior when exiting fullscreen on macOS
Resolved
Attachments
Comments 36
Right now there is no way to 'set' the 'new' fullscreen mode. I'll ask LWJGL if they can add it, and if so, we can use that instead when pressing F11.
And what about the fact that if you enter "minecraft" fullscreen while in native fullscreen then exit it, the window is incorrectly sized and shows the bar at the top.
@unknown: have you heard back from LWJGL yet? If not, it might be better to just remove the F11 shortcut, as suggested by @unknown.
Here is the LWJGL thread: https://github.com/LWJGL/lwjgl/issues/83
Actually, I think this issue has been resolved. I'm unable to make the game crash and while it's super glitchy while switching into Minecraft fullscreen it doesn't seem to cause any real problems.
When you said you reproduced it, what do you mean by "it"? Just going into the secondary fullscreen? I'm in 1.20.4
Not sure I understand your comment but it seems like we agree that steps 1-4 of the description are WAI and steps 5-6 are no longer an issue, while the issue with ctrl is now covered by MC-268226. This being the case, a WAI here seems appropriate.
I was experimenting a bit more and was able to reproduce the issue or a variant on it that can take over this ticket.
In some versions of the game I'm able to crash the game and in others I'm able to end up with a frameless window (no title bar with close/minimize/expand button).
If F11 works for you, use that. I used the Full Screen button in Video Settings to accomplish this:
command+control+F to enter native fullscreen
Full Screen button in Video Settings
command+control+F again
Full Screen button in Video Settings
At this point, my computer screen is mostly black/or blurry. I press command+control+F one more time and the game exits full screen but has no window controls (close, minimize, expand etc.). The window is sometimes larger than my screen and sometimes smaller.
In prior versions (1.19) this crashed the game.
I see. I was also able to reproduce this and took a couple of screenshots using shift+cmd+4+space.
[media][media]
Well, there shouldn't be two fullscreen modes because that would be just stupid. So either remove the F11 shortcut for the original fullscreen or make that toggle the OS X fullscreen. Anything else is totally confusing and buggy.